<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>

</body>
</html>
<script>
    var x= 1,y=z=0;
    function add(n){
        return n=n+1;
    }
    y=add(x);
    function add(n){
        return n=n+3;
    }
    z=add(x);
    console.log(x);
    console.log(y);
    console.log(z);
</script>